even more progress

patches/server/0067-Use-a-Shared-Random-for-Entities.patch

@@ -0,0 +1,42 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Tue, 22 Mar 2016 00:33:47 -0400
+Subject: [PATCH] Use a Shared Random for Entities
+
+Reduces memory usage and provides ensures more randomness, Especially since a lot of garbage entity objects get created.
+
+diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
+index e9e87dc8c80d83dc7c472b0611077d8f9f4e5fcf..eceaeed527f34860e1c55b9f96863f140055faa7 100644
+--- a/src/main/java/net/minecraft/world/entity/Entity.java
++++ b/src/main/java/net/minecraft/world/entity/Entity.java
+@@ -153,6 +153,21 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, n
+         return tag.contains("Bukkit.updateLevel") && tag.getInt("Bukkit.updateLevel") >= level;
+     }
+ 
++    // Paper start
++    public static Random SHARED_RANDOM = new Random() {
++        private boolean locked = false;
++        @Override
++        public synchronized void setSeed(long seed) {
++            if (locked) {
++                LogManager.getLogger().error("Ignoring setSeed on Entity.SHARED_RANDOM", new Throwable());
++            } else {
++                super.setSeed(seed);
++                locked = true;
++            }
++        }
++    };
++    // Paper end
++
+     private CraftEntity bukkitEntity;
+ 
+     public CraftEntity getBukkitEntity() {
+@@ -304,7 +319,7 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, n
+         this.bb = Entity.INITIAL_AABB;
+         this.stuckSpeedMultiplier = Vec3.ZERO;
+         this.nextStep = 1.0F;
+-        this.random = new Random();
++        this.random = SHARED_RANDOM; // Paper
+         this.remainingFireTicks = -this.getFireImmuneTicks();
+         this.fluidHeight = new Object2DoubleArrayMap(2);
+         this.firstTick = true;